Bement said Greenspan was an investor in his heroin business, and that just before the killing, he told Greenspan they'd never do another drug deal together. Greenspan had become too unreliable, Bement said.

For the prior six months, Bement said, Greenspan had also "laundered" money that Bement acquired in street-level drug sales. That task consisted of Greenspan converting small-denomination cash into larger bills for use in large-scale drug deals, Bement said.

On March 13, 2010, Bement testified, he went to Greenspan's house to pick up $20,000 that Greenspan was supposed to have changed into large bills. With that money and another $6,000 that Bement already had on him, they took Greenspan's rental car to purchase a kilo of heroin for $25,000 in Cornelius, Bement said. All of that money technically belonged to Bement, he said, although he owed Greenspan about $7,200.

En route to their destination, Bement learned that Greenspan hadn't laundered the money. The pair stopped in the cemetery to count the cash, he said. Greenspan was in a front seat as they argued, he said, while Bement was in the back.

"I looked up and (Greenspan) was pointing the gun, and he said, 'Give me the (expletive) money,'" Bement testified.

"When I looked up and he was holding that gun at my face, the look in his eyes was a person I'd never seen before," Bement said. "When we went for that gun, there was no question in my mind that this man was trying to kill me."

"I put my hands up, I grabbed the gun, it went off," he said.

Bement said he saw a flash in his lap and heard a loud bang when the gun fired into the backseat. The gun fell to the floor of the backseat, Bement said. Both men reached for it, but Bement got to it first. When Bement sat upright with the firearm in his hand, Greenspan was in the midst of turning around to face the front windshield.

"I just started pulling the trigger," Bement said. "I just started pulling the trigger."

The incident passed in a matter of seconds, Bement said, and he acted instinctively.

Bement said he heard "gurgling noises" as Greenspan struggled to take his last breaths. He opened the rear passenger door, stumbled out of the car and began dry-heaving. He wiped the gun across his sweatshirt and tossed it into the backseat. Then he grabbed the money and ran.

"I would say that I wish I could take it back and he was alive, but I was saving my own life," Bement said. "I wouldn't say he deserved to die, but I felt that I deserved to live."